Two speed tuning dial



June 1956 J. w. FORREST 2,751,788

TWO SPEED TUNING DIAL Filed Feb. 8, 1955 jl mmflz a? 4% June 1956 J. w. FORREST TWO SPEED TUNING DIAL 2 Sheets-Sheet 2 Filed Feb. 8, 1955 United States Patent Two SPEED rUNnsG DIAL him] W. Forrest, West Acton, Mass, assignor to Acton Laboratories, Inc., Boston, Mass.

Application February 8, 1955, Serial No. 486,857 6 Claims. c1. 74-1052 This invention relates to tuning dials, and more particularly to such dials having a fine and a coarse speed dial face with the fine speed dial face disconnectable from its 'coarse speed drive.

It is accordingly an object of this invention to provide a new and improved two speed tuning dial.

Another object of this invention is to provide a two speed tuning dial in which the lower speed dial can be disconnected from the higher speed dial by the same hand turning the higher speed dial.

Another object of this invention is to provide a two speed tuning dial in which the lowerspeed dial can be disconnected from the higher speed dial While such higher speed dial is being turned.

It is still another object of this invention to provide a two speed tuning dial in which the lower speed 'vernier dial can be readily disengaged from the higher speed coarse dial for rapidly moving the tuning dial to a particular setting.

Another object of this invention is to provide a two speed tuning dial in which the lower speed dial can be disconnected from the higher speed dial so that the lower speeddial can be readily reset.

Another object of this invention is to provide a two speed tuning dial in which the higher speed dial has a particular ratio of travel with respect to the lower speed dial.

Another object of this invention is to provide a two speed tuning dial of simple design and 's'n'iall size having a 'wide range of speed ratios.

Another object of this invention is to provide a two speed tuning dial having a 'i'ninimu'm number of moving parts.

A further object of this invention is to provide a two speed tuning dial which is smooth and reliable in operation.

A still further object of this invention is to provide a two speed tuning dial in which all parts are readily accessible for repair purposes.

Otherobjects andadvantages of the invention will be apparent during the course of the following description when 'read in connection with the accompanying drawings, wherein:

Figure 1 is a side elevation view showing the entire tuiiing dial;

Figure 2 'is across-sectional elevation view taken at section 2-2 of Figure 4;

V Figure 3 is a cross-sectional view taken at section 3- -3 of Figure 2;

Figure 41's a front view of the two speed tuning dial face;

I Figure 5 is a sectional view taken at section 5-5 of Figure 2; and

Figure6 is a cross-sectional view of the split gear and clutch taken at'section 66 of Figure 3 'Refer'ring now more particularly to Figures 1 and 2 or the drawing, there is shown a housing 10 having a ice 'tiuding through two washers 12 fastened by means or screws 13 and covering circular openings 20 and at both ends of the housing. The housing '10 is mounted on wall sections 14 by means of two screws 15. The main shaft 11 may be coupled to or extended at the rear end of the housing by any appropriate means. These extension means do not form anyipan of this invention and will not be any further described.

The housing 10 consists of a square shell '16 having a plate 17 covering the rear of the housing and a plate 18 covering the front of the housing. The plate 17 is secured to the shell 16 by four screws 19, and has a central circular aperture 20 covered by one of the previously mentioned washers 12. The plate 18 is secured to the shell 16 by screws 15 and two screws 21, and has a central circular aperture 22 covered by the other washer 12.

The main shaft 11 is inouhted in the plate '17 by means of a bearing 23 positioned in the aperture 20 against a trimmer spring washer '24, which in turn is retained in the aperture 26 by thewa'sher 12. The spring washer 24 acts to bias the mounting bearing 23 to eliminate any radial play which can appear as backlash in the tuning dial.

An outer sleeve shaft 25 is rotatably mounted on the inner main shaft 1-1 by two bearings 26 and 27. The

one beai in'gZS consists of balls 28 retained between the main shaft 11 and the sleeve shaft 25 by a washer 29', the main shaft, and 'a 'racefor ined by undercutting sleeve shaft '25 to fo'f'm a cup-like retaining surface 30. The other bearing 27 consists 'of balls ti-retained by a race formed by undercutting sleeve shaft 25 to form a cup-like surface 32, the main shaft '11, and "two washers '33 positioned on main shaft 11 by retaining ring 34 which is set into a recess 35 of the main shaft '11. A spring wave washer 36 is positioned between the washers '33 to maintain continuous contact between the balls 23, 31 and sleeve shaft 25. The main shaft 11 and the sleeve shaft 25 are mounted in the plate 18 by'inean's of a bearing 37 positioned in the aperture 22 and held in longitudinal position on one side by the washer 12 and on the other side by a retaining ring 38 which is set into a recess '39 of the sleeve shaft 25.

A bushing "40 is positioned on the front end of the main shaft 11, which extends beyond the 'end of the sleeve shaft mounting bearing 27. A dial knob 42 is fastened through the bushing 40 to the shaft 11 by a set niain shaf-t-'11-positioned centrally-in the housin'g'and'prot screw 43. Ah aperture 41in the knob 42 provides access to the set screw 43. An inner circular dial 44 is mounted by three screws 45 to'the rearfac'e 46 of the dial knob 42. The dial 44 is the coarsedial and may be calibrated in'angular units, such as degrees, 'alongits circumference,

Referring 'now more particularly to Figure 6, a sleeve hub 47 is fixed in position by set screws 48 on the main shaft 11. The sleeve hub '47 has a shoulder 49 at one end of the hub, Slidably mounted on thehub '47 is a washer 56 having one face adjacent the shoulder 49. Three set screws 57 are provided inshoulder '49 to'p'ositidn the washer'56 along thea'xis o'f thehub'47. A s'pring Washer 59, having its convex surface engaging the other face of the Washer '56, is 'slidably mounted on the hub 47. A flat washer 51 is slidably positioned against the concave surfaceof the spring washer'50. A split gear 52, connected for anti-backlash action by a spring 53, "is slidably mounted on the hub 47. The gear 52 is prevented from sliding off the hub 47 and limited in axial motion on the hub 47 by two retaining rings 54 and 55. Two Washers58 and '59 are disposed against eachof the innersurfaces 60, 6170f the split gear 52.

A dial hub 62 'is fiigedly connected with a set screw 63 to the sleeve'shaft 25 "closeto'thesleeve"shaft meuiiting bearing A flange provides the mountings'url 3 face for a circular outer dial 65. The outer dial 65 is mounted to the flange 64 by three screws 66. Dial 65 has a knurled edge for ease of operation. Two screws 92 mount an index indicator 67 through spacers 68 to wall section 14 (see Figure 1).

A fixed gear 69 is mounted by three screws 70 to a circular plate 71, which in turn is mounted by three screws 72 to the front plate 18 of the housing 10. Both the fixed gear 69 and the plate 71 are concentric with the main shaft 11 and the sleeve shaft 25. The gear 69 and the plate 71 have central apertures sufficiently large to clear both shafts.

An arm 73 is mounted on the sleeve shaft 25 and fixed to the shaft by a set screw 91. The sleeve shaft 25 passes through a circular openingv 74 at the center of the arm 73. At one end of the arm 73 is a hole 75 Within which is rotatably supported a shaft 76 on ball bearings 77 and 78. The bearing 77 consists of balls 79 re- I tained between the shaft 76 and the arm 73 by a washer 80, the shaft 76, and a race formed by chamfering hole 75 to form a retaining surface 81. The bearing 78 consists of balls 32 retained between the shaft 76 and the arm 73 by a washer 83, the shaft 76, and a race formed by chamfering hole 75 to form a retaining surface 84. Backing up the washer 83 along shaft 76 is a spring wave washer 84 and another washer 85 in that order and retained in contacting position by the retaining ring 86 fed into shaft 76.

A pinion gear 87 is mounted at one end of the shaft 76 and meshes with the fixed gear 69. Another pinion gear 88 is mounted at the other end of the shaft 76 and positions the washer 80 against the balls 79 of the bearing 77. The pinion gear 88 meshes with the split gear 52 (see Figures 3 and 5), and thus provides the drive for the sleeve shaft 25 and outer dial 65 from the main shaft 11. Two counterweights 89 are mounted in the arm 73 to oppose and balance the forces acting on the shaft 76.

Referring to Figure 4, there is shown a front view of the dial face. The inner dial 44 and outer dial 65 are positioned concentrically with the dial knob 42. As previously mentioned, the inner dial 44 is fixedly attached to the dial knob 42 and rotates with it at all times. The transparent index indicator 67, having an index line 90 scribed upon its face, is mounted onto the wall section 14 by screws 92 (see Figure l). The index line 90 serves as a reference line to permit reading and adjusting both the inner and outer dials.

Referring again to Figure 2 for a description of the operation of the two speed tuning dial, it is seen that that knob 42 turns the inner dial 44 and the shaft 11 directly at all times. The friction clutch shown in detail in Figure 6 is adjusted by means of set screws 57 to slip at the torque input normally applied when turning knob 42. Thus rotation of the inner dial 44 by turning knob 42 causes the split gears 52 to slip on their mounting sleeve 47, and, as a result, no rotation of the outer dial takes place. This permits the inner dial to be set independently of the outer dial 65.

When the outer dial is rotated, the inner dial and knob rotate at a fixed speed ratio to the outer dial as determined by the interconnecting gear train combination consisting of the split gear 52, the intermediate gears 87, 88, and the fixed gear 69. Rotation of the outer dial 65 turns its dial hub 62, which in turn rotates the sleeve shaft 25. As the sleeve shaft 25 revolves, it carries with it the arm 73. Since the shaft 76 is mounted on the arm 73, this shaft will now revolve with' the arm 73 "about the shaft 11. Upon being set in motion, the shaft 76 causes the gear 87 to rotate against the fixed gear 69. This rotates the shaft 76 and its attached gear 88 in its bearings 77 and 78. In turn, gear 88 rotates the split gear 52 which drives the sleeve hub 47 through the clutch formed by the spring washer 50 bearing against the washer 56. To

. A set the outer dial independently of the .inner dial, the inner dial must be manually restrained.

While I have shown and described my invention in connection with certain specific embodiments, it will, of course, be understood that I do not wish to be limited thereto, since it is apparent that the principles herein disclosed are susceptible of numerous other applications, and modifications may be made in the structural arrangement and in the instrumentalities employed without departing from the spirit and scope of my invention asset forth in the appended claims.

I claim as my invention:

1. A two speed tuning dial comprising a housing, a main shaft through said housing rotatably-supported therein, inner and outer circular dial faces concentric With said shaft, a dial knob mounted on one end of said main shaft and connected to said inner dial face, a first sleeve mounted rotatably on said main shaft and having said outer dial face connected to it, a second sleeve having a shoulder at one end mounted fixedly on said main shaft, a first friction disk mounted on said second sleeve and having one face against said shoulder, an anti-backlash gear mounted rotatably on said second sleeve, a retaining ring mounted in said second sleeve and against said anti-backlash gear to retain said anti-backlash gear on said sleeve, a second friction disk mounted rotatably on said sleeve against said anti-backlash gear between said first friction disk and said anti-backlash gear, said first and second friction disks being spring biased to hold said anti-backlash gears against said retaining ring, an arm mounted fixedly on said first sleeve, a pinion shaft mounted rotatably in one end of said arm, a first pinion gear mounted on said pinion shaft and engaging said anti-backlash gear, a fixed gear mounted concentric with said shaft and connected to said housing, a second pinion gear mounted on said pinion shaft and engaging said fixed gear so that as said outer dial face is rotated said inner dial face rotates at angular speeds having-a fixed ratio to the angular speed of said outer dial face, said dial knob rotating said inner dial face independently of said outer dial face.

2. A two speed tuning dial comprising a housing, a main shaft rotatably supported therein, inner and outer circular dial faces concentric with said shaft, a dial knob mounted on one end of said main shaft and connected to said inner dial face so that rotating said knob will cause a corresponding angular displacement of said main shaft and said inner dial face, a sleeve mounted rotatably on said main shaft and having said outerdial face connected to it, a second sleeve mounted fixedly on said main shaft, :1 gear mounted rotatably on said second sleeve, a friction clutch interconnecting said second sleeve and said gear, an arm mounted fixedly on said first'sleeve, a pinion shaft mounted rotatably in one end of said arm, a first pinion gear mounted on said pinion shaft and engaging said gear, a fixed gear mounted concentric with said shaft and connected to said housing, a second pinion gear mounted on said pinion shaft and engaging saidfixed gear so that as said outer dial knob is rotated said inner and outer dial faces are rotated at angular speeds having a fixed ratio to each other, said dial knob rotating said inner dial face independently of said outerdial face.

3. A two speed tuning dial comprising a housing, a main shaft rotatably supported therein, inner and outer circular dial faces concentric with said shaft, a dial-knob mounted on one end of said main shaft and connected to said inner dial face so that rotating said knob will cause a corresponding angular, displacement of said main shaft and said inner dial face, a first sleeve mounted rotatably on said main shaft and having said outer dial face connected to it, a second sleeve mounted fixedly on said; main shaft, a gear mounted rotatably on said, second sleeve, a friction clutch interconnecting said second sleeve and said gear, and means interconnecting said gear and said first sleeve so that as said outer dial knob is rotated with .said friction clutch engaged said inner and outer dial faces are rotated at angular speeds having a fixed ratio to each other, said dial knob rotating said inner dial face independently of said outer dial face.

4. A two speed tuning dial comprising a housing, a main shaft through said housing rotatably supported therein, inner and outer circular dial faces concentric with said shaft, a dial knob mounted on one end of said main shaft and connected to said inner dial face so that rotating said knob will cause a corresponding angular displacement of said main shaft and said inner dial face, a sleeve mounted rotatably on said main shaft and having said outer dial face connected to it, gearing means interconnecting said shaft and said sleeve, a friction clutch interposed between said first shaft and said gearing means normally operable so that as said outer dial knob is rotated said inner and outer dial faces are rotated at angular speeds having a fixed ratio to each other, said dial knob rotating said inner dial face independently of said outer dial face when said clutch disengages said gearing.

5. A two speed tuning dial comprising a housing, a main shaft rotatably supported therein, inner and outer circular dial faces concentric with said shaft, a dial knob mounted on one end of said main shaft and connected to said inner dial face so that rotating said knob will cause a corresponding angular displacement of said main shaft and said inner dial face, a sleeve mounted rotatably on said main shaft and having said outer dial face connected to it, gearing means coupled to said sleeve, a gear connected to said housing and engaging said gearing means, a second gear connected to said first shaft and engaging said gearing means, a clutch connected between said main shaft and said second gear so that as said outer dial knob is rotated with said clutch engaged said inner and outer dial faces are rotated at angular speeds having a fixed ratio to each other, said dial knob rotating said inner dial face independently of said outer dial face.

6. A two speed tuning dial comprising a housing, a main shaft rotatabiy supported therein, inner and outer circular dial faces concentric with said shaft, a dial knob mounted on one end of said main shaft and connected to said inner dial face so that rotating said knob Will cause a corresponding angular displacement of said main shaft and said inner dial face, a sleeve mounted rotatably on said main shaft and having said outer dial face connected to it, a second sleeve mounted fixedly on said main shaft, a gear mounted rotatably on said second sleeve, a friction clutch interconnecting said second sleeve and said gear, an arm mounted fixedly at its center on said first sleeve, a pinion shaft mounted rotatably in one end of said arm, a counter-weight mounted in the other end of said arm, a first pinion gear mounted on said pinion shaft and engaging said gear, a fixed gear mounted concentric with said shaft and connected to said housing, a second pinion gear mounted on said pinion shaft and engaging said fixed gear so that as said outer dial knob is rotated said inner and outer dial faces are rotated at angular speeds having a fixed ratio to each other, said dial knob rotating said inner dial face independently of said outer dial face.

References Cited in the file of this patent FOREIGN PATENTS 254,147 Great Britain July 1, 1926 

